The invention relates in general to the production of chocolate, and in particular to a method of and a device for the continuous production of a chocolate mass from a non-refined cocoa mass which still contains undesired aromatic substance and moisture, finally ground and mixed to a degree required by the final prescription and also contains all usual constituents except fat, water and emulsifier.
These constituents, as known, are sugar only when producing dark chocolate, or sugar, milk powder and cocoa butter in the case of milk chocolate mass.
In producing chocolate masses it is conventional to grind and mix raw stocks and, in order to create the desired aromatic and tasty quality as well a favorable processing quality of the pretreated mass, the latter is subjected to a simultaneous mechanical and heat treatment. This refining process, which is called a tumbling treatment in a conche represents with respect to the quality of the final product the essential part in the technological process in the manufacture of chocolate mass.
In order to make this refining process of the chocolate mass more effective, numerous tumbling methods and kinds of conches have been devised relating either to individual processing stages or to the entire manufacturing process.
As is generally known, prior-art tumbling treatment in a conch which is based on discontinuous processing is very time-consuming and requires considerable energy input, to intensify tumbling treatment in existing conches by means of improved machinery, definite limits have been encountered for such improvement.
Analyses of technological processes have resulted in modern solutions of the tumbling processes in conches. It is known for example that by using a dry tumbling treatment in conventional, discontinuously operating conches, the overall period of the entire process is shortened; nonetheless, the high consumption of energy remains unchanged. Also, various processes have been devised combining the grinding, the mixing and the tumbling treatment in conches. For example, a method and a device is known in which the mixing and grinding of the chocolate components takes place in a recirculating process whereby the chocolate in each repeated circle runs through consecutively arranged mixing and grinding devices, and during the recirculation is sprayed in the form of a film or band which encounters one or more separate streams which are taken up by the chocolate mass. This stream or streams can be of gas, for example an air stream. In this manner solid particles can be gradually optimized until a fluid phase of the chocolate mass is attained; in this fluid phase the chocolate mass is again grated in a grinding device whereby upon each passage a renewed mixing and introduction of one or more separate gas streams takes place. The device required for carrying out this circulation process occupies a small space. Nonetheless, this method brings about no substantial time and energy savings; neither does it facilitate a continuous discharge of the chocolate mass. This known method is suitable for the manufacture of chocolate masses having a high fat content (German published patent application No. 1 902 778).
Furthermore, methods and devices have been developed in which the process of refining the chocolate mass has been intensified by separating in time and place the individual-process stages such as the removal of moisture and undesired substances from the processing stages concerning the plastification and homogenization. The refining process of the chocolate mass is hereby carried out either continuous or discontinuously. In doing so, the cocoa mass before its mixing with other usual components is subjected to a preliminary treatment to drive out moisure and undesired substances. These impairing substances and moisture are removed from the cocoa mass in such a manner that the mass is kept in a fluid condition and continuously advanced while additional water is continuously added, and this additional water is emulsified with the mass during its advance whereupon the mass is spread into a thinner layer and the layer is degasified by ventilation or under the effect of vacuum (German published patent application No. 2 313 563; DE-WP No. 98 817). In another known continuous process the chocolate mass prepared from the pretreated cocoa mass is rolled, liquefied and finally homogenized in a homogenizer by the effect of shearing forces and simultaneously a direct current of air and nitrogen is guided through the chocolate mass. The disadvantage of this known method is the fact the the intended exchange of substances between the gas stream and the chocolate mass in fluid condition takes place only partially (German published patent application No. 2 238 519).
Known also are a method of and a device for manufacturing milk chocolate masses, in which the cocoa mass is alternately mixed with added charges of cocoa butter and milk powder. The discharge in corresponding two mixing containers is effected so that a continuous stream of cocoa mass is created which is subsequently subject to spreading into a thin layer for the purpose of dehydration. Subsequently, cocoa butter, lecithin and sugar are added to the demoistured cocoa mass and the resulting mixture undergoes alternately a charge homogenizing process. The discharge of the finished mass occurs batchwise, whereby the individual batches or charges are unified into a continuous stream. The device employed for carrying out this method includes substantially as main processing stations a charge mixer, a refining unit in which the mass is spread into a thin layer, a continuous kneading machine, a milling device and additional mixers. It is evident that in practice this known method requires a complex machinery with corresponding high technological expenditures, whereby it does not ensure any completely continuous treatment (DD-publication No. 123 570).
Furthermore, a continuous process for manufacturing chocolate masses is known which differs from the foregoing method in preparation by means of a preliminarily refined cocoa mass of a low fat basic mixture which is rolled in a known manner. The resulting basic mixture in the form of a dry, friable rolled product is intensively treated by means of activation of limit surfaces without any additional dehydration. Thereupon, dehydrated cocoa mass, cocoa butter and lecithin are added. The resulting chocolate mass which now corresponds to the final recipe is again exposed to an intensive shearing load and liquefied. In order to process the rolled semiproduct, there are provided containers for plasticization and an additional container for homogenization of the chocolate mass, whereby each container is equipped with a cross beam mixing mechanism cooperating with intermeshing fingers mounted on the inner walls of the container (DDR publication No. 108 451).
Even by means of this method, which also requires the application of a pretreated, dehydrated cocoa mass, the aforementioned disadvantages pertaining to the previously discussed methods of this kind, namely a high expenditure on machinery and high production costs, are not avoided.